Inserted tooth tool



Patented Sept. 10, 1946 UNIT-ED .STATES PATENT 0F FICE INSERTED Toorn amori 7v viifrea slater, Quinton, Birmingham, England. l

Application september 16, iaiaseriazmn. .states v @Claims Tl'l'ris invention relates 'to metal working 'tools such as hubs, breaches., taps, andthe like, .of 'the kindincluding a' supporting body .and a plurality of .cutting elements mounted thereon.

Theobject of theinventionis ya process .and/or means for forming or grinding cutting elements or teeth 'in a simple rapid manner which yields the desired form or allows "1t to be subsequently realised by a simple operation; which elects a considerable saving in labour and machine time.;

(Cl. Bil-1.05)

' grinding wheeror ineiikeasuepicied in .the .righi and which lengthens the effective working life of the velementsand consequently'the tool jinto which they are built.

Having 'the aforesaid and other objects in View as will Aappearin ,the Iollowing description, the invention Yconsists in a bodyor holderfor the cntting elements of inserted'tooth tools which Vis so shaped and constructed that the peripheral .surfaces of the elements when assembled .on the body can be machinedground, or similarly processed as segments of .a `common circle which when the elements are reassembled in working or Vcutting position, Vprovide relief away .from the cutting edge. zIn'this way, a simple turning, grinding, or like roperation which can .be Vcarried out on a standard kind ,o'f'machine 'tool is substituted for the 'more numerous and complex operations previously needed.

VFurther features vofthe invention .are more particularly described inthe annexed .speciiicationV andy pointed out .in the appended claims.

Reference may be 'had to 'the .accompanying drawings in which 'Figure l is an end view partly in sectionpar.tly inelevation o'f.atool^according tothe invention.,

Figure 2 is a .half sectionalelevation at vright angles to Figure .1.

Figures 3 and 4 illustrate other lapplications .of cutting elements .made in .accordance with the invention.

Figures 5 and '6 depict the .improved cutting elements mountedin Workingposition on amodied body.

,In an embodiment .QI `.the .invention shown in Figures 1 .and 2, the '.bod-y l .is provided with .a number .of longitudinal `.seating .surfaces or grooves 2 each .of whichis shaped .and .inclined or Vcurved to suit the under .tace of .a .cutting Aelement '3 Lwhich `said .tace is .preerably flat.) .and tilt .or .hold the .element so .that its periphery V4 becomes a segment of a circle or is .susceptible of taking such a curve when the body is rotated aboutfitslongitudinal `aids and the peripheral surfaces of the several cutting elements are in contact with and are operated upon by a cutting tool,

half -of Figure l. In this position andduringsuch process, the rearedge .5 ofeac-h element is farther from the eentrefofithe .body than it is when placed in :a cutting .or working positionsuch .as shown in the left half :of Figurel so that when reassembled in the Working position for use as acutterzbyvre versal .or displacement through 180J the .newpositionrelative to or :measured from the body ,centre .provides the desired relief :away rfrom the .eutting edge, the effect .being to yexchange .the posi-r tion of :the iront and rear edges. The dotted line yat the top .of Figure ,1. shows the working position .of .a segment .superposed .on its making position.

Cutters Ymamita.ctur'ed .in the manner described by .collective yfabrication .can be reassembled .in either` of two ways; one, .on a body of normal .type preferably modified; .the other, on the same body as is used .for making the cutters. In the latter case,.the ,leading face .of .the .cutting .element is tangential unless modified i.. .e. rit has :negative rake, but this can be ground to an anglewhi-ch provides Vpositive .rake .as `indicated at 5 in '.Fig-

.l ure 1.

A Suitable blank for cutting .elements in minar manufacture .consists :of a length .of .tour-sided bar with .anat 'base 2, two sides converging at an appropriate .angle which vis determined by 'the and .for .manufacturing use, the `.door .or .base of eachseatinggroove 2 is atright angles to a radial line ,from .the corner which leads whenfcu-tting, when said corner 'l is in position for making, the blank .sides diverge isogenically, and .the leading face B of ythe element .makes .an .angle with the radial line il .one-.half of that included bythe two sides .8 lib.A The peripheral longitudinal grooves .2 are .of sawtooth fconguration the long limb of which constitutes .the seat A2 and the .short limb il of which =defines 'the .circumferential position .of the ,relevant element. The several -ele'- ments are adapted to be .assembled in such a manner that .each one abnts and is abutted by At each of the two ends of the body is situated a clamping plate I2 of disc shape inset into a recess partly in the insert element and partly in the body end, these being pressed home by screws, preferably countersunk. Such endwise and also a radial movement is transmitted to each element by the agency of inclined planes conveniently in the form of a cone-ended vscrew I4 in the disc and a complementarily-shaped cavity I5 in each end face of each element, the arrangement being such that the thrust from the screw ends is translated into resultants acting at an angle to the end faces. To ensure this action, a slight clearance (shown exaggerated) is provided in the cavities. By clamping the end plates in position, the elements are collectively and individually located and gripped so that they function as a solid body.

When the elements are displaced through an angle of 180 to bring them into cutting position, the rake or angle of the leading face is, as beforementioned, of a negative order which is appropriate for some metals; grinding of the faces to provide positive rake can be effected by conventional tools and methods preferably when the elements are disassembled, though they can be 'ground in situ.

As the cutting edges of the elements become worn, they can be sharpened and restored time after l"time by regrinding until they are almost worn away, since they are buttressed by the adjacent face of the proximate element which gives solid and adequate support; therein the improved elements differ from known cutters in which the members are separated by spaces. This continuity characteristic of tools according to the invention provides a smoother cutting action and assists in obtaining greater accuracy.

The contour of the periphery of the cutting elements is adaptable to the form required e. g, straight, formed (an examplebeing indicated by dotted lines I6 Figure 2) threaded for -thread milling, etc.

Cutting elements manufactured as described may, as adumbrated, be assembled on and used with a normal type body the periphery of which has a number of longitudinal flats which form seats for the bases of the cutters. Thus a body isillustrated in Figures 5 and 6 wherein the ends of the cutters are frustroconoidal in shape, to engage with similarly coned collars I1, I3 one of which is screwed on the end of the body and the other is pressed by a nut I9 at the other end. To improve location of the several cutters, I propose to add an upstanding ring 20 at or about the middle of the body and groove the underface of each insert to fit closely thereon. In this modification, the leading face 8 of the cutting elements is radial, as is a line drawn through the centre of each cutter.

Cutters made according to the invention are obviously capable of utilisation in diverse forms of tools in which a series of cutting elements is secured to a body, and also when a single tool is employed. Figure 3 shows a cutting element 3 fixed in the tool post 2| of, say, a lathe, while Figure 4 illustrates a broach the body 22 of which carries in series several cutters. Other applications will be self-evident.A

Having thus described my invention, what I claim is:

y 1. Means for supporting independent tooth tools comprising a circular body formed for sup- 4 porting independent tooth tools for simultaneous shaping into cutting elements and subsequently supporting said cutting elements in cutting position, said body being peripherally formed with immediately successive recesses to present flat seats and tooth tools having at bases to seat in said recesses and bear throughout on the iiat seats, the extended lengths of thetools beyond the recesses being in relatively mutua1 contact throughout the circumferential length of the body to present the free ends of the tools remote from the body as relatively rigid segments of a common circle to permit desired shaping of the ends of-thetools in a single operation under rotation of the body, the formation of the seats, the cooperating ends of the tools and of the tools beyond the seats providing for a movement of the formed tools throughout 180 to arrange the tools in cutting position on the body with the tools having a Vsubstantially identical cooperationwith the seats and with each other beyondthe seats in the cutting position as in the forming position.

2. Means for supporting independent tooth tools comprising a body peripherally formed with recesses having flat seats and tooth tools to cooperate with the seats, each of the tools having sides converging toward the seats and a flat end to engage the fiat seat of a recess with such at end, the converging sides of the tools being in mutual contact beyond the seats in all positions of the tools relative to the body, the tools'having two relatively reversed positions with respect to the body, one to dispose the tools for making the cutters and the other to dispose the tools as cut-- ting elements with respect to the body, the tools in either position having a flat bearing on the flat surfaces ofthe recesses and a mutual contact beyond the flat surfaces throughout the peripheral length of the body. 3. A construction as defined in claim 2 wherein in either position of the tools relative to the body, the tools extend beyond the body in mutual contact to dene a continuous ring of metal composed solely of the cutters in either of said positions, whereby to establish a regiditive position, a continuity of function and an extreme accuracy in operation.

4. Means for supporting independent tooth tools comprising a body peripherally formed with recesses having flat seats and tooth tools to cooperate with the seats, each of the tools having sides converging toward the seats and a flat end to engage the iiat seat of a recess with such iiat end, the converging sides of the tools being in mutual contact beyond the seats throughout the circumferential length of the body to present the free ends of the tools remote from the body as relatively rigid segments of a common circle t0 permit the desired shaping of the ends of the tools in a single operation under rotation of the body, and means for supporting the shaped tools comprising an independent body peripherally formed with flat seats to cooperate with the formed tools, the sides of the tools converging towards the seats and the iiat ends of the toolsl engaging the flat seats with such flat ends presenting an equal angle to each of the converging sides of' the tools, the converging sides of the tools being in Amutual contact beyond the seats throughout the peripheral length of such independent body.

WILFRED SLATER. 

